Hi, just entered ToL 2 weeks ago. Is it intended that in ToL you cannot change spell gems from e.g. lesser to minor?
Hard to say what's intended and not this expansion. Just /bug report it in game and in the bug section, let the Dev team figure it out.
The ability to convert claimable spell runes from a higher level to a lower level within the same expansion, traditionally goes active only a few months after the expansion is live, in the past few expansions. So I estimate that the rank 2 runes should start being convertible from 120->119->118->117->116 versions a bit later. Just right now they are not convertible.